Casing structure for internal-combustion free piston engines



1946- R. P. RAMSEY 2 4,7

CASING STRUCTURE FOR INTERNALJ-COMBUS TION FREE PISTON ENGINES Filed March 17, 1945 I H 8 a awe/whom Rummy AMEEY PH E g Patented Aug. 20, 1946 FElC CASING STRUCTURE FOR INTERNAL-con- BUSTION rare rrs'ron ENGINES Robert P. Ramsey, Hamilton, Ohio I Application March 17, 1945, Serial No.583,33 i

This invention relates to free piston engines of the internal combustion type, and particularly to such an engine used in connection with turbines to supply gas under pressure thereto.

An object of the invention is the provision of an engine frame or casing construction composed of a plurality of sections which are separably connected to permit easy access to the internal parts for inspection, replacement and repair.

Another object of the invention is the provision of liner means for the cylinder forming the combustion chamber and in which the power pistons operate, which means is removably fitted into the cylinder in a manner to permit easy replacement, and which provides an efficient bearing surface for the pistons and also provides a water-jacketing feature.

Other objects and advantages of the invention will be apparent from the following detailed description and from the accompanying drawing illustrating one embodiment of the invention, in which Fig. 1 is a central longitudinal section of the engine frame With the parts thereofin assembled relation and with the customary free pistons at the outer ends of their strokes and in full; Fig. 2 is an enlarged fragmentary section the same as in Fig, 1, and of one end portion thereof, and Fig. 3 is an enlarged cross-section on the line 3-3 in Fi 1.

Referring to the drawing, l designates the center frame of the engine, which frame is of cylindrical form and has a liner 2 forming the cornbustion chamber 3 in which a pair of opposing free pistons 5, 4, constituting the power pistons of the engine, operate. The frame I ateach end terminates in a radially enlarged cylindrical extension 5 that is coaxial with the chamber hand is provided, in the present instance, at its outer end with an outwardly projecting radial flange B.

A ring I abuts against the outer end of the extension 5, being secured to itsflange 6 by stud bolts 8, and has a cylindrical liner part 9 projecting therefrom into the extension 5 to cooperate therewith and with the ring 1 to form the circumferential wall of a cylinder inwhich an air compressor piston 10 of the engine operates This piston is attached to the outer end of the power piston 4 to move therewith and divides the interior of the compressor cylinder into areverse bounce chamber H and an air compressor chamber l2.

Attached to the outer end of each ring l by the 13011758 is a head It for the air compressor cylinder and this has'a central cylindrical open- 14 Claims. (01.123-46) q a. a ing through which a bounce piston I l projects outwardly from the piston H] centrally thereof into a bounce chamber l5 formed as hereinafter described. The head l3 has a hollow outward extension is which is radially spaced from the chamber l5 and has its inner wall or that adjacent to said chamber of conical form which narrows thesaid spacing inwardly from the outer end of the extension.

A liner H, which constitutes the cylinder in which the piston it operates and which forms the chamber I5, is fitted into the centralopening of the compressor cylinder head It and. has its outer end portion radially enlarged as at it to abut against the outer end of the extension l6 and to be attached thereto by stud bolts IS. A bounce cylinderhead. 2! is removably attached to the outer end of the liner H by stud bolts 22. The liner H, in surrounding relation to the bounce chamber l5, forms an annular chamber 25 which communicates with the outer end portion of thechamber l5 through one or more ports -25, thus forming an enlargement for the bounce chamber. The extension t5 and liner I-l cooperate to form a space therebetween which is'divided into an air chamber 21 anda coolant circulating chamber 28 by a sheetmetal-sleeve.29that is Welded at its endedges to shouldered portions of the liner. A circulating coolant is introduced into the chamber 28 in any suitable manner.

Air to be compressed in each chamber i2 is admitted thereto through.one .or, more inlet openings 30 in the ring I, which iopenings communicate with the atmosphere through asupply chamher or manifold 3i and with the compressor chamber l2 through suitable inwardly opening valves 32. Outwardly opening discharge valve means Sit-is provided in the compressor cylinder head It and open outwardly into the hollow of the head extension l6 and-thence through a surrounding chamber or manifold to a scavenging receiver 35. This receiver; as is customary with engines of this character, connectsthe chambers 34 at both ends of the engine and, in the present instance, has its sole discharge into the com bustion chamber-through a passage 36 surrounding the combustion chamber and in communication therewith through an annular series of ports 31. These ports are uncovered by one of the pistons when near the outer end of its the compressor gas is to be supplied. The ports 7 38 are uncovered by the other power piston 4 when near the outer end of its stroke and the length and arrangement of the scavenging ports 3'! and exhaust ports 36 are such that the exhaust ports are opened in advance of the scavenging ports and remain open during the entire period that the latter ports are open. 1

The power cylinder liner 2 may be inserted into position within the frame part I from an end thereof and has a fluid tight connection therewith at spaced points lengthwise thereof so that a cooling fluid may be circulated inspaces 4! provided therebetween. These spaces are in communication lengthwise of the liner through passages 43. The outer sides of the spaces, 4| may.

be, and in the present instance are shown as being, separated from outwardly registering space portions 42 of the frame part I by sheet metal strips 44 welded thereto at their ends and hav-- ing expansion portions 45 therein to facilitate contraction and expansion of the sizes of the spaces 4| under changing temperature conditions. The .walls of the passages 3Band 39. are jacketed, as shown at 46, to facilitate the circulation therearound of a cooling fluid.

The wall of the air compressor cylinder formed by the'extension 5 and liner 9 may be cooled by the circulation of a cooling fluid through a passage 41 provided around the cylinder between such parts.

It is apparent from the foregoing that the frame or casing of the engine includes a plurality of separable parts joined together to form the cylinders for the working pistons 4, the compressor pistons I and the bounce pistons. l4; that these parts may be easily and quickly assembled or disassembled; that by removal of the bounce cylinder head 2| the interior of the bounce chamber l5 may be inspected; that the liner 1'! forming the bounce cylinder may be removed together with the headZl by simply removing the bolts 1 9, thus exposing the sides as well as the ends of the bounce piston l4, that the compressor cylinder head (3 together with the parts carried thereby may be removed from the compressor cylinder by removal of the bolts 8 and that thering I and its liner 9 may also be removed from the cylindrical extension 5 upon a removal of said bolts. The removal of the head 13 permits inspection of the operating parts carried thereby and also permits removal ofthe piston sets from the engine casing and after this the power cylinder liner 2 may be removed for inspection or, replacement.

I wish it understood that my invention is not limited to any specific construction, arrangement or form of the parts, as it is capable of numerous modifications and changes without departing from the spirit of the claims.

Having thus described my invention, what I claim as new, and desire to secure by United States Letters Patent, is:

1. In an internal combustion. free piston engine, a casing structure including a center frame part serving in part at least to form an open ended piston receiving power cylinder having an enlarged longitudinally extending cylindrical part at each end and a liner for said extending part to .provide a cylinder for receiving an air compressor piston and a removable head for each of said. latter parts forming a cylinder for receiving a bounce piston, a removal of said heads rendering accessto the different cylinders.

2. In an internal combustion free piston engine, a casing structure including a center frame forming a power'cylinder and having at each end a longitudinally extending cylindrical enlargement with its outer end open, a head removably attached to said enlargement and having an extension projecting therein and forming a liner therefor to form an air compressor cylinder, said head also forming a bounce cylinder, said power, compressor and bounce cylinders being axially aligned and opening one into another and adapted to respectively receive the power, air compressor and bounce pistons of the engine.

3. In an internal combustion free piston engine, a casing structure including a center frame forming in part at least a power cylinder and having at each end a longitudinally extending cylindrical enlargement with its outer end open,

said enlargement forming in part at least an air compressor cylinder, a head removably attached to the outer end of each of said enlargements and having a part removable therefrom and forminga bounce cylinder, said power, compressor and bounce cylinders being axially aligned and opening one into another and adapted to respectively receive the power, the air compressor an bounce pistons of the engine.

4. In an internal combustion free pistonengine, a casingstructure including a center frame forming a liner receiving cylinder open at each end and also having at each end a longitudinally extending cylindrical enlargement, a liner in said cylinder forming a power chamber, a head for said enlargement having a cylindrical extension projecting therefrom into said enlargement to cooperate therewith to form an air compressor cylinder, said head also forming a bounce cylinder, said several cylinders being axially aligned and adapted to successively receive the power, air compressor and bounce pistons of the engine.

5. In an internal combustion free piston engine, a casing structure including a cylindrical center frame part, a liner in said part forming a power cylinder, said part and liner having circulating passages therebetween for a cooling fluid, the outer ends of said frame part having radially enlarged axial extensions, and means removably attached to the end of each of said extensions and having a liner part projecting therefrom into the extension to cooperate therewith to form an air compressor cylinder, said latter part and extension having provision therebetween for the circulation of a cooling fluid, said means forming a head for the compressor cylinder and a bounce cylinder at the outer end of the compressor cylinder, said power, compressor and bounce cylinders being adapted to respectively receive the power, the air compressor and bounce pistons of the engine.

6. In an internal combustion free piston engine, a casing structure, including a center frame, a liner removably cooperating therewith to form a powercylinder, said frame having at each end a longitudinally projecting radially enlarged extension, a ring removably attached to said extension and having a liner projecting therefrom into the extension and cooperating therewith to form the circumferential wall of an air compressor cylinder, said ring having air inlet open,- ingstherein to said cylinder and a head removably attached to said ring for closing the outer the cylinder, and means removably carried by said head and providing a liner projecting therein to form a bounce cylinder, said. power, com-f pressor and bounce cylinders being adapted torespectively receive the power, compressor and bounce pistons of the engine.

7. In an internal combustion free piston engine, a casing structure including a central part of cylindrical form having at each end a longitudinally projecting radially enlarged extension, a liner removably mounted in said cylindrical frame part to form a power chamber, a liner removably mounted in said extension to cooperate therewith to form a compressor cylinder, a head removably attached to said extension and second liner to close the outer end of the compressor cylinder and having a central opening, said head having a hollow outward projection surrounding its center opening and having its inner wall substantially conical in form with its large end outward, and means attached to said head extension and forming a liner for projection into the center openings of said head and its extension to form a bounce cylinder, said power, compressor and bounce cylinders being adapted to respectively receive the power, compressor and bounce pistons of the engine.

8. In an internal combustion free piston engine, a casing structure including a central frame part forming power and air compressor cylinders, a head attached to said part at each end and closing the outer end of the compressor cylinder, said head having a central opening and an outer hollow extension around said opening and forming a compressed air receiving chamber having an outlet, said head having valved discharge passages between said compressor cylinder and chamber, and sleeve means removably attached to the outer end of said head extension and projecting within said extension and to the center opening of the head to form a bounce cylinder and an auxiliary chamber in communication with said bounce cylinder, said power, air compressor and bounce cylinders being adapted to respectively receive the power, air compressor and bounce pistons of the engine.

9. In an internal combustion free piston engine, a casing structure including a central frame part forming power and at each end an air compressor cylinder, a head attached to said part at each end and closing the outer end of the respective compressor cylinder, each of said head having a central opening and an outer hollow extension around said opening and forming a compressed air receiving chamber having an outlet, said head having valved discharge passages between said compressor cylinder and chamber, and sleeve means removably attached to the outer end of said head extension and projecting within said extension and the center opening of the head to form a bounce cylinder and an auxiliary chamber in communication with said bounce cylinder, said power, air compressor and bounce cylinders being adapted to respectively receive the power,

air compressor and bounce pistons of the engine, said head extension and liner means having provision therebetween for the circulation of a cooling fluid.

10. In an internal combustion free piston engine, a casing structure including center means forming a power cylinder and at each end thereof the circumferential and inner end walls of an air compressor cylinder which is enlarged relative to the power cylinder and is coaxial therewith, head means removably attached to each end of said center means and closing the outer ends of the respective air compressor cylinders, said head means having a central opening and a hollow outward extension surrounding said opening together with valved discharge passages from the compressor cylinder to the hollow of said eX- tension and an outlet passage therefrom, and means removably attached to the outer end of said head extension and including a liner projecting within said extension and head opening to form a bounce cylinder in axial alignment with said other cylinders, said power, air compressor and bounce cylinders being adapted to receive the respective power, air compressor and bounce pistons of the engine.

11. In an internal combustion free piston engine wherein a set of connected power, air compressor and bounce pistons operate at each end, means forming a power cylinder for the power pistons and at each end thereof a portion at least of a cylinder for receiving the respective compressor piston, means at each end completing the respective compressor cylinder and forming a compressed air distributing chamber in check valve controlled communication with the compressor cylinder, said last means having an opening concentric to the compressor cylinder with its wall including said distributing chamber, and means mounted in said opening and forming a bounce chamber for the respective bounce piston.

12. A structure as called for in claim 11 wherein the last means is radially spaced from the wall of said distributing chamber to provide a cooling fluid circulating space therebetween.

13. A structure as called for in claim 11 wherein aid last means includes a supplemental chamber which surrounds and is in communication with said bounce cylinder and is disposed partially at least within said opening.

14. A structure as called for in claim 11 wherein said last means includes a supplemental chamber which surrounds and is in communication with said bounce cylinder and i disposed partially at least within said opening and wherein a cooling fluid circulating space. is provided between said distributing chamber and a considerable portion of said last means.

ROBERT P. RAMSEY.

Certificate of Correction Patent No. 2,406,037. August 20, 1946. ROBERT P. RAMSEY It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Column 3, lines 68, 69 and 70, claim 1, strike out the words and a liner for said extending part to provide a cylinder for receiving an air compressor piston and insert the same in line 72, same claim, after piston and before the comma; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 5th day of November, A. D. 1946.

LESLIE FRAZER,

First Assistant Gammz'ssz'oner of Patents. 

